Convertible ringing control for telephone systems



6. 0. WULF. CONVERTIBLE RINGING CONTROL FOR T ELEPHONE SYSTEMS.APPLICATION FILED SEPT. 20. 1913.

I, 1 ,1 95, 1 63. Patented Au 15, 1916.

2 SHEETS-SHEET I.

i 2/ 227525555: Jim/E2775 I G n; WOLF. CONVERTIBLE RINGING CONTROL FORTELEPHONE SYSTEMS.

APPLICATION FILED SEPT. 20,1913- 1,195,163. Patented Aug. 15, 1916.

2 SHEETS-SHEET 2- Z 27 7 5555: jz'zuezvifin GEORGE n. oL IoEc Ic eo,rumors,assiolvon'rofkErLoed-swlronnoannfAND f SUPPLY COMPANY, orCHICAGQILLINQIS,,AQORPORA'IION orrnnmo slj CONVERTIBLE imvcme CONTROLFOR TELEPHONE sYsTEMs. e

To all whom it may concern Be .it known that I, GEORGE'D. Worm, acitizen of the United States of America, residing in Chicago,'county ofCook, and State of Illinois, haveinvented certain new and usefulImprovements in "Convertible Ringing Control for Telephone Systems, ofwhich the following is a specification.

My invention relates to'telephone systems '10 and is directed moreparticularly to alternative methods for controlling the application ofringing current. That is-my invention looks more to a ringing systemwhich may be readily converted from automatic to manual ringing, anobject of my inventionbeing to provide a simplified circuit arrangementof this character which is alsopositive and xyetlicient in operation.

In telephone systems wherein automatic 2o ringing is provided andwherein constantly operating mechanism is provided, such as, aninterrupter, although during the day service when a great manyconnections are being established such automatic ringing is an opkcrating advantage, nevertheless during times when few connections arebeing established a ers lines, I have provided animproved cord,'

circuit arrangement in whiclrnieans areiprovidedso that the momentringing" key" 40 plunger 18 depressed (whenthe cord circuit is'used forautomatic r nging),-rmgmg curing end of the cord circuit, no matter inwhat position the interrupter mechanism may be in. The interruptermechanism thereafter operates to "intermittently apply ringing currentto the said line; By so arranging the cord circuit, that is, byprouidfing it with the above described so-called preliminary ring, Ihave saved a great deal of time in the average time that it takes! Iiternate position. When a rmgmgplunger from the moment that the ringingkey plunger is depressed until the called subscribers bell is firstoperated. a I For a better understanding of my inven- Specification ofLetters Patent.

tion reference will be had to the accompanycontacts 3,4, 5, or. 6 arePatented Application filed September 20, 1913. Serial No. 790,814

ing drawings in which like reference char;

acte'rs indicate like parts and in which- Figure 1 illustrates atelephone, system'l having two-conductor line and cord circuitsv 6 0embodying my invention; and Fig. 2 illus-I 'trates as telephone systemof the so-called; three-conductor type, and which embodies,

my invention; v. H Referring now more particularlyltoth systemillustrated in Fig.1, it comprises fa, call ng substation A and-calledsubstation; connected to line circuits C and, D respecl tively. A cordcircuit E ifor interconnect mg said lines is provided, said lineandacid? clrcuitsbemg of the two-conductortype, An" answering supervisoryrelay AS is provided: at the answering end of the cord circuitfandi sadapted, when the answeringe plug '1 is msertedinto a jack of thecalling line, 7.5, .ll

automatically connect an operators phone 0 in circuit With the cord.

In connection with the callingendof circuit E, I have provided a callingplug 2 and a so-called switching relay SW, which; 89. A

may also be called a supervisoryv control re; lay, said relay S W beingadapted to be ener if gized when the calling plug 2 is inserted into thejack of a called line whereb'y the op erators telephone 0 isoperatively. di'scbn'f 8,5 nected from the cord. A calling supervisoryrelay CS, sometimes referred to as a tip re-J lay, is also providedbeingadapted to be en ergizedwhen a response is secured front the, called,substation, to controlthe supervisory: 9Q

signal and the automaticringing circuit.

' A ringing key 'RK is also providedbeing preferably of the type havingringing'and indicating positions andcomprising agpl urality ofindependently operablejringing 9 5. contacts 3, 4, 5, 6, together With'aset, if

rent is automatically connected to the'callcommon contacts 7, 8. When aplungeris taming the ringing contacts in theIr'al is-depressed, the slowacting disconnect re; lay DR its-energized and maintained 'ener: gizedwherebya-ci'rcuit for interrupter relay IR is established from theinterrupter I. This efi'ects an intermittent energization of theinterrupter relay IR to periodically apply ringingcurrent according tothe actuated plunger. When the called subscriber responds, relay CSoperates to interrupt the locking circuitior relay DR whereby theringing current is disconnected. When it is desired to use the automaticringing control, the switch S, which may be common to a plurality ofcords, is moved into its dotted position but when the manual control isdesired switch S is moved into its open position. Thus, when manualringing is de sired, switch S being in its open position, no circuit isestablished from the interrupter for the interrupter relay IR but eachtime ,a ringing plunger is fully depressed so as "to actuate commoncontacts, 7, 8, relay IR operates to apply ringing current. hen thesubscriber answers, relay CS operates to restore the disconnect relay DRas before thereby establishing the continuity of the talking circuit,but of course in this instance it does not effect the interrupter relayIR. In connection with the ringing apparatus I preferably employ ringinggenerators of different frequencies using call bells at the substationscorresponding to the ringing.

generators employed.

Referring now more in detail to the operatlon of the system of Fig. 1,upon the removal of the receiver at calling substation A, line relay LRis energized to light the calling signal 9 in the usual manner wherebythe operator will insert an answering plug 1 into a jack 10 of thecalling line. This connects the cutoff relay CO and impedance coil 11 inseries to energize said relay CO. Therefore the calling line isconnected in circuit with the answering end of the cord circuit E and acircuit for answering supervisory relay AS is established traced frombattery through the winding of 11 over the calling line and returninthrough the wind ing of AS to ground. Relay AS therefore interrupts itsnormal contact 12 to open the circuit of signal 13 and upon the closingof alternate contacts 14, 15, of AS, the operators telephone 0 isconnected over conductors 16, 17, and through normal contacts 18. 1!),to the cord circuit conductors.

The operator now ascertains the wants of the calling subscriber andfinding that connection is desired with the line of substation B, a jack20 of the called line is tested in the usual manner to determine itsidle or busy condition, and finding that said line is idle-the operatorinserts the calling plug 2 into the jack. A circuit including switchingrelay SWV and cut'oif relay CO is therefore established causing theenergization of these relays whereby opera tion of CO extends connectionfrom the plug 2 to substation B and removes the normail control of itsline relay LR". Responsive to energization of SW, its alternate. contact21 is closed establishing a circuit for supervisory signal 22 over thenormally closed contacts 23, while the interruption of normal contacts18, 19, of SWV disconnects the-operato1"s telephone 0 from the cord.Furthermore the interruption of normal contact 24 of SW disconnects thetest conductor 25 and by closing of alternate contact Qiestablishing thecontinuity of the tip strand.

Assuming now that the automatic ringing control is in service and theswitch S is in its closed or dotted position, upon the operatordepressing the proper ringing key 3, 4e, 5, or'6 to its fully actuatedposition, alter natecontacts 7, 8, thereof are closed. The closing ofalternate contact 8 establishes an energizing circuit for relay DRtraced from battery through the winding thereof, alternate contact 8,conductor 26, normal contact 23, and alternate contact 21 to ground. Atthe same time alternate contact 7 is closed connecting the said groundedconductor 26 in circuit with the interrupter relay IR and whereby itsalternate contacts 27, 28, are closed connecting ringing current to thecalled line. This connection of ringing current to operate the call bellof the called subscriber as just described may be termed a oreliminar Trin and is a )lied innnediatel upon the depression of a key plunger to afully depressed position due to the momen tary closure of the end spring7. Should the operator hold the depressed plunger in its fully actuatedposition for a short time the call bell of the called subscriber wouldbe continuously rung until the .key plunger is allowed to restore to itsindicating position at which time the interrupter mechanism is connectedin circuit to bring about the intermittent application of ringingcurrent to the call bell of the called subscriber as will now bedescribed. Upon energization of DR, its alternate contact 29 is closedestablishing a locking circuit for DR through normally closed contact 23of the supervisory relay CS and the grounded alternate contact 21.Therefore, although the initial energizing circuit'for DR is interruptedat alternate contact 7, when the operator removes the pressure upon theactuated key, relay DR remains energized and therefore an intermittentenergization ofinterrupter relay IR is eliected by current from batterythrough the winding. of IR, normal contact 7, alternate contact 30,switch S'and interrupter I to ground. Relay IR therefore is alternatelyenergized and de'c nergi'zed, alternately connecting ringing current andsupervisory relay CS in bridge of the called line. During theapplication of ringing current, it will be noted that the talkingconductors of the COIdCIICUItS are inter.

rupted at normal contact 31, 32 of DR so as to prevent ringing backoverthe'calling line.

Dueto the current charge of the called line which is caused by theperiodic application ofringing current, relay; CS receives the dischargefrom the line each time normal. contact 27 of IR is closed. This willcause relay CS to momentarily open the circuit .of DR,but DR being aslow acting relay, it requires a proloiiged interruption of its holdingcircuit to eflect the restoration thereof.

Upon a response being secured from the called substation, and upon thefollowing deenergization of IR, a circuit for relay CS is establishedfrom ground through the winding of CS, normal contact 27, alternate Icontact 24 over the called line returning '7, 8, close as through thewinding of SW to battery. Relay CS therefore energizes, interruptingitsnormal contact 23 whereby supervisory signal 22 is efiaced and theholdin circuit for relay therefore restores establishing the continuityof the talking conductors and alsointerrupting the operating circuitforrelay IR,

After the subscribers have finished con versation they will replacetheir receivers upon their respective switch-hooks whereby the circuitsfor relays AS and CS are in terrupted causing the restoration of theserelays and lighting supervisory signals 13,

plugs from the connected spring jacks 10, 20, and thereby brings aboutthe restoration of the apparatus employed.

Assuming now 'that manual ringing 1s being employed and that the switchS is in its open position, when the operator fidepresses a ringingplunger alternate contacts before whereby relays DR and I IR" energize,relay DR remaining looked as e already pointed out.

plunger is restored, relay IR restores and ringing key,

;But when the ringing type of ringing to the other, it is only necestoactuate the switch 93.Referring now to the embodiment invention asillustrated in Fig.2, the difference in this systeig, over that shown inFig. 1 is that three con uctors are employed at the jacks andplugs,wh1le in Fig. 1 but two conductors are employed,

sary

Fig of my principal kick up its armature and DR is interrupted. Re ay DRQAS is established over the calling line.

The operator therefore withdrawsthebe is brought about frorn theforegoing.

Therefore the cut-off relays of the threeconductor line circuits areconnected to a third contact of the jack and a battery conthe thirdcontact ofnection is provided for the answering plug 1 while at. thecalling '7 plug '2 the third contact .is connected to the winding ofswitching relay SW so that relays SW and 00* are connected in series tobring about their energization.v Also I- have provided a two-windinganswering s supervisory relay AS connected in bridge of the talkingconductors of the cord, and a two winding calling supervisory relay CSin bridge of the talking conductors at the calling end of the cord. r

The corresponding parts of the systems of Figs. 1 and 2 are indicatedbyjlike reference 3 characters, except in Fig. 2 the sufiix prime. I

is, added.

Now as to,the operation of the system of Fig.2, whenjan answering plug 1is inserted into a jack.10 .o f a calling line, the cutoif relay CO isenergized over a circuit 111- eluding the third; contacts of jack 10 andlug 1 and a circuit for supervisory relay 9e Relay AS therefore connectsthe operators telephone 0 in circuit-with the cord in a] manneras beforedescribed while when the calling plug 2 is inserted into a jack 20 .95

of a called line, relays SWV of CO are'energized over a series clrcultto brin about the disconnection of the operators te ephone" O and-thelighting of supervisory signal 22 The actuation ofthemringingapparatusof cord circuit E is identical with the operation oftheringing apparatus of cordcircuit E.

Upon a response being secured from called-substation B the callingsupervisory -1Qiirelay CS is energized by current over the called linewhereby its normal contact 23 is interrupted to bring about thesupervisory and ringing control as described in connection with the cordcircuit E.

When the subscribers at substations A and B have finished. conversation,they will replace their receivers upon theirrespective 1 switch-hookswhereby the circuits for supervisory relays AS and OS are interrupted1.15

to effect the operation of the supervisory signals 13 22 -Upon theoperator withdrawing plugs 1 and 2 from the connected spring jacks, theapparatus used in establishir the connection is restored to, nor- 1.2K;

mal in a manner as previously described;

In the several embodiments ofmy invention illustrated, well-known formsof line and substation circuits are shown together with well-known formsof supervisory api it is to be understood that I- paratus and I applyingmy 1nvent1on in other contemplate ways than that shown and I aim tocoverall such modifications as come within'thes pirit and scope of theappended cla ms.

Having described my invention, what I claim as new and desire to secureby United States Letters Patent is:

1. A telephone system comprising a called telephone line, an operatorslink circuit connected thereto, a ringing key, ringing control relays, asource of rlnging current, circuit connections for said key and relayswhereby when said key is operated an automatic and intermittentapplication of ringing current to the called line is efi'ected, and asingle pole manually controlled switch for changing said circuitconnections whereby the automatic and intermittent control is remoredand an application of ringing current to the said called line from saidsource of current is positively effected by each operation of saidringing key.

A telephone system comprising telephone lines, opcratofis link circuitsfor connection thereto, a ringing key for each of said circuits, ringingcontrol relays for each of said circuits. a source of ringing current,circuit connections for each of said keys and associated relays wherebywhen a key is operated an automatic intermittent application of ringingcurrent to a connected called line is established, and a single polemanually cimtrollcd switch common to said link circuits for changingsaid circuit connections whereby the automatic intermittent control isremoved and an application of ringing current to a connected called lineis positively effected by eaclr operation of a key. i

it. A telephone system comprising telephone lines, an operatofs linkcircuit focconnection thereto, a rin in key rin in control P: n .J t: in

relays, a source of ringing current, circuit connections for said keyand relays whereby when and key is operated an automatic in termittcntapplication of ringing current to a connected called line isestablished, and a single pole manually (:ontrolled switch for varyingsaid circuit connections to remove said automatic intermittent controland whereby an application of ringing current is positively effected byeach operation of said key.

t. A. telephone ,systeui comprising telephone lines, operators linkcircuits for connection thereto, a ringing key and ringing y controlrelays for each of said link circuits, a source ol rmgnlg current,cn-ciut connections for each key and associated relays whereby when oneof said keys is operated an automatic intermittent application ofringing current to a connected called line is established, a singlepolemanually controlled switch common to said link circuits for varyingsaid circuit connections to remore said automatic intermittentcontroland wherebynirapplication ot ringing current is positively elt'ected byeach operation of one of said keys.

5. A telephone system comprising a called telephone line, an. operatorslink circuit connected thereto, a ringing key, interrupter anddisconnect relays, an interrupter adapted to be placed in circuitrelation with the interrupter relay by an energization of saiddisconnect relay, circuit connections whereby an operation of saidringing key will energize said relays to periodically apply ringingcurrent to the called line, and a manually operable switch fordisconnecting said interrupter to place saidv relays under manualcontrol of said ringing key.

6. A telephone system comprising :1. called telephone line, an operatorslink circuit connected thereto,a ringing key, interrupter and disconnectrelays, an interrupter adapted to be placed in circuit relation with theinterrupter relay, a manually operable switching device adapted fordisconnecting said interrupter, circuit connections where by anoperation of said ringing key will energize said relays and place saidinterrupter in circuit relation with said interrupter'relay to applyringin current to the called line, and means w ereby when saidinterrupter is disconnected from the interrupter relay by said manualswitch said relays are manually operative by said ringing key.

7. A telephone system comprising it called telephone line, an operatorslink circuit connected thereto, a ringing key, ringing control relays,an interrupter adapted to be placed in circuit relation with one of saidrelays to ell'ect intermittentoperations thereof, a source of ringingcurrent connected in circuit with the called line upon each suchoperation of'said relay, circuit connections whereby an operation ofsaid ringing key will; cause operation of said relays to effect suchperiodic application of ringing current, and a single pole manuallyicontrollcd switch for opening the circuit of said interrupter wherebysaid circuit connections are effective to place said relays under mansaid interrupter circuit is rendered inctl'ective and whereby ringingcurrent is applied only while said key is held operated.

1). A telephone system comprising a subscribers line, a link circuit forconnection to said line a ringing control relay for said link circuit,means for intermittently operating said relay, starting means for starting such intermittent operation, said starting means adapted to cause apreliminary operation of. said control relay. IOY' telephone systemcompri scribers line, a substation thereon, a link circuit adapted to beconnected to said line, automatic ringing means for said link circuit, aswitching device for starting the'op: eration of said ringing meanswhereby said substation is intermittently signaled, and means controlledby said switching device for transmitting a preliminary signal to saidsubstation. Y 1' 11. A telephone system comprising a subscribers line, asubstation thereon, a manual link circuit provided with automaticringing means adapted to be connected to said line, a ringing keyplunger for causing the operation of said automatic ringing meanswhereby said substation is intermittently signaled, and means controlledby said ring ing plunger for insuring that said substation will besignaled the instant that said.

ringin plunger is operated.

12. n a telephone system, the combination of a subscribers substationand a link circuit connected thereto, automatic ringing means for saidlink circuit, a switching device for starting the intermittent operationof said ringing means whereby said sing a subsubstation isintermittently signaled, and means for insuring that the said substationwill be signaled the moment that said switching means is operated.

13s A telephone system comprising a subscribers lineprovided with asubstation thereon, alink circuit for connection to said subscribersline, a ringing relay for said link circuit, an interrupter device forintermittently operating said relay whereby said substation may beintermittently signaled, and independent means for energizing said relayto cause a'preliminary signaling oper ation atsaid substation.

14;. 'A telephone system including a subscribers telephone line, a linkcircuit for connection to said line, means for applying ringing currentto said line, an inter-. rupter device for intermittentlyoperating saidmeans, and an electrical switch for first operating said means and for,ttliereafter connectmg said interrupter devlce 1n circuit with saidmeans.

Signed by me at Chicago, county of Cook and Stateof Illinois, in thepresence of two

